Process for producing alkyl alkyl-phosphonochloridates



United States Patent 3 167 574 PROCESS FOR PRObUClNG ALKYL ALKYL- PHOSPHONOCHLORIDATES Bernard B. Brown, Leland J. Lutz, Charles J. Smith, In,

ice

radicals. Thus, in accordance with our invention we react the phosphonate:

with from 1.0 to 1.3 molar amounts of phosgene at 55- and Earl weilinuenster Niagara Falls N' assign 5 85 C. and at a pressure of 50-500 p.s.i.g., thereby rapidly to dgfflg Chemical Cameraman a carpi) producing a high yield of the desired product with minira one in b ducts L 404 373 mum formation of y pro No Drawmg. i higiiif The following test runs illustrate various embodiments 7 10 which fall within the scope of our invention and wh ch Our invention relates to a method for the preparation Were Performed at eqhlhhflllm Pressure 111 the fellewlhg of certain monochloro compounds by phosgenation. er to produce the compound: 1

More particularly, our invention concerns a method in 1 p o p o (CH3) which certain phosphonates are used as a starting mate rial and in which the following reaction takes place: g ggggi from dusopropyl methane Phospnonate (R0)(R' ")-i- }f J P O R RC1 CO (i-PrO) P(O) (CH (cl) 2 50 grams of distilled diisopropyl methane phosphonate and helng alkyl radlcals' was charged to a 25-0 ml.-capacity stainless steel pressure F r Vari u reasons, the Carrying out Of h afore' vessel which was fitted with a 500 pound gauge gradumentioned reaction to Produce the monochloro com ated in 5 pound units. To the vessel and contents, chilled PoundS of the formula: in a Dry Ice-acetone bath, was added 31.6 grams of liquid Cl 1 P O phosgene. The vessel was quickly sealed and placed into a heating unit maintained at about 10 C. above the a a pid rate and in good Yield based p the amounts desired reaction temperature. Stirring of the reaction of reactants taken is difiicult of attainment. One of those mixture was started immediately ft the reaction reasons is the tendency of the ester used s Stefhng perature was attained, about 10 minutes being necessary terial to v r l r ua to form diehlole pe to reach temperatures of 80 C., and was continued for which r not/the desired Products of the Present mventhe duration of the run. The reaction vessel was quickly tion. Dichloro compounds represent reactant loss and transferred from the heater to the Dry Ice-acetone bath, furthermore react with the starting ester, thereby reducb way of an i Water b th d l d til th gauge ing the amount of such ester in the reaction mixture pressure remained constant. After the carbon dioxide available for conversion to the d s mOIIOChIOIO COITI- was vented, the contents of the vessel were degassed for pound. Other reasons why it is difficult to carry out the 30-60 minutes at 50-55 C. and 25-35 mm. of mercury,

desired reaction rapidly and in good yield are found n d di ill d at d d pressure, the tendency of the monochloro compound desired as a Table I below sets forth the operating data and results product to condense with itself, and also to react Wi h t e obtained in these tests:

Table I Experiment N 0.1"- 1 2 5 3 4 9 Diisopropyl methane phosphoriate, gm 50 50 50 5O 50 Diisopropyl methane phosphonate,moles 0. 278 0.278 0. 278 0. 278 0.278 0. 278 Equilibrium Pressure, lbsJsq. in. gauge 155-215 200-255 245-305 330-380 320-380 Temp, C 50-55 -60 69-76 82-90 96-109 Total gm. Phosgene 31.6 31.6 31.6 31.6 31.6 31.6 Mole ratio, Phosgene/Diisopropyl methane p p'nnnate 1.15 1.15 1.15 1.15 1.15 1.15 Stirring time, min 15 15 15 15 15 15 Total reaction time, min. 27 23 27 20 21 19 Degassing Period, Min 45 45 45 45 45 45 Wt. of degassed prod., gm 44. 2 42. 7 40. 0 41.4 41. 8 35.9 Distillation press., mm. Hg-.- 1. 5-2.3 3 2-4.8 1 6-2.2 1 6-2.3 4.2-6.0 1. 7-3.5 Distillat on vapor temp, C. 46-52 47-64 41-43 41-45 49. 5-57 34. 543 Wt. of distillate, gm 34. 2 26. s 29. 1 37. 0 37. 0 23. 0 Wt. of residue, 5. 2 s. 1 7. 2 3. 2 1.1 0. 42 Ratioresidues/distillata O. 152 0. 310 0. 248 0. 087 0. 030 0. 42 Hydrolyzable C1 in distill-at 14. 90 18.70 20.10 21.17 22. 9s 23. 37 Percent Purity Product. 65. 8 82.5 88.8 93. 5 99 97. 5 Wt. of pure Product, gm 22. 5 22.2 25. 8 34.6 36. 6 22. 4 Wt. of pure Product, moles 0. 144 0.142 0. 165 0.220 0.234 0.143 Yield of Product based on Diisopropyl methane phosphonate, percent 51. 7 51.0 59. 4 79. 5 84. 3 51. 5

The data of Table I illustrate the importance of operating Within the limits of the present invention in carrying out the reaction. Thus, it will be noted that when the reaction temperature of 30 C. was used the residue/ distillate ratio was somewhat lower than when a reaction temperature of 50-55 C. was used. This is not to be expected, but can possibly be explained by the slow rate of anhydride formation at 30 C. When the reaction temperature was increased from 5055 C. to 8290 C. the residue/distillate ratio decreased with increased reaction temperature, but with reaction temperatures of 96- 1-09 C. the residue/distillate ratio rose sharply due not only to increased anhydride formation but to condensation of dichloro by-product with diisopropyl methane phosphonate and of product with itself.

A further series of test runs Was made using the procedure just described, With the exception that the pressure in the reaction vessel'was maintained at 125 pounds a p sum of the carbon atoms in R and R preferably not exceeding 8 and the number of carbon atoms in R" preferably not exceeding 4. Thus, vR and R' can be, 'for example, methyl, ethyl, n-propyl, n-butyl, Z-ethylhexyl and 5 v the like and R can be, for example, methyl, ethyl, nper square inch gauge by venting the carbon dioxide. propyl, i-propyl, n-butyl, i-butyl and the like. 7 Since it was desired to maintain the bulk of the phosgene We claim: I I I in the liquid state, the maximum temperature utilized was I A method for the preparation of a compound of the about 75 C. The operating data and results obtained in formula: this series of runs are set forth in Table II below: (C1) (RO)P(O) (R").

Table II Experiment N 61. 63 G7 73 75 Diisopropyl methane phosphonate, gm 50 50 50 50 50 Diisopropyl methane phosphonate, mole 0.278 0.278 0.278 0.278 0.278 Operating Pressure, lbs/sq. in. gauge--. 125 125 125 125 125 Temp., O 69-72 e9-90 69-72 72-75 74-76 Total gm. Phosgene 33.1 33.1 33.1 33.1 33. 1 Mole ratio, Pliosgene/DiiSopropyl methane phosphonate. 1. 2 1. 2 1. 2 1. 2 1. 2 Stirring time, min 2O Total reaction time, min. 27 29 20 10 Degassing Period, min 45 45 45 45 Wt. of degassed product, gm. 42. 4 41. 3 42. 1 42. 2 Distillation press, mm. Hg 1. 0-3. 5 2. 8-3. 4 2.0-4.0 2. 0-2. 3 1. 5-2. 6 Distillation vapor temp., 26-50 48-51 41-52 52-56 -51 Wt. of distillate, gm 38.2 38.9 38.2 38.0 38.8 Wt. of residue, Hm 2.0 2. 2 .1. 7 2. 2 2. 2 Ratio, residues/distillate 0. 053 0.057 0.045 0.058 5 0.057 Hydrolyzable C1 in distillate.--" 22. 4s. 22. 32 22. 20 22. 68 22. .10 Percent Purity Product..- 99. 0 98. 5 98. 0 100- 98 Wt. of pure Product, gm. 37.8 38. 3 37. 4 q 38 37. 8 Wt. of pure Product, moles 0. 242 0. 245 0. 239 0. 244 0. 242 Yield of Product based on Diisopropyl methane phosphonate, percent 87 88 86 88 87.5

Various modifications can be made in the specific prowhich comprises reacting a compound of 'the formula: cedures just described to provide other embodiments R0 P O R which fall within the broad scope of our invention. Thus, 35 u I our invention is generally applicable in the preparation of With from t9 IIIQMTamOUmS 0f Phosgelle at a compounds f th formula; temperature Within the range -85 C. and a pressure within the range 50-500 p.s.i.g.,-R and R beingisopropyl (C1) (R OJHO) (R radicals and'Rf being'a methyl radical. by reacting compounds of the formula? 40 N f p H ore er'ences' cited.

with phosgene under the conditions specified. In the two preceding formulas, R, R and R" are alkyl radicals, the

CHARLES B. PARKER, Primary Examiner.

WILLIAM G. WILES, c. D. QUARFORTH, Examiners. 

